Vegetation as an indicator of high wind velocity

and root dry weights. A significant influence to growth of trees is
caused by constant wind velocity is the conclusion of the article.
Holroyd, E.W. III, 1970: Prevailing winds on Whiteface Mountain as
indicated by flag trees., Forest Science, 16, 222-229.
The direction of prevailing winds was determined by the study
of flag trees on Whiteface Mountain in the New York Adirondack area.
Using both the direction of branch growth and the position of the
reaction wood in the trunk tops, a very complex wind pattern was found.
Tree-flagging indications of the wind should be very useful, when combined
with a topographic map, the direction of the wind wiI.1 show regions of
rising or subsiding air. Tree-flagging can show areas of exposure to
strong winds and the drying associated with them.
Jacobs, M.R., 1936: The effect of wind on trees. Austral. For. 1: 25-32.
The purpose of this article is to discuss the means of preventing
the unnecessary damage which is caused by wind on trees and the observa-
tions of wind damage on trees. When any tree is subjected to a force
which continually acts in one direction such as a prevailing wind, it puts
on uneven annual rings which change its normal circular cross section to
an elliptic with the long axis running down the wind. Wind acting on the
higher center of gravity of the crown of the high crowned tree has a
greater turning moment than in the case of deep crowned trees.
Jacobs, M.R., 1954: The effect of wind sway on the form and development
of Pinus radiata. Austral. J. Bot. 2: 35-51.
Free swaying trees grew more in diameter over the lower part of
the trunk than stayed trees. The effect of sway at the height of 4 ft
was greater in a very heavily thinned test area than in a well-stocked
test area. Sway caused increased growth of roots near the trunk and
increased eccentric trunk development along the line of main winds. The
height growth of stayed trees was little different from that of the free
swaying trees, but height/diameter relationships were changed. After two
years, trees that had been prevented from swaying were no longer stable
in a normal environment.
Jacobs, M.R., 1939: A study of the effect of sway on trees. Austral.
Commonw. For. Bur., Bul. No. 26. 17 PP.
This paper describes the experiments designed to determine the
effect of sway on tree growth. Two kinds of trees, P. radiata and
E. gigantea,were chosen as samples, four test plots G-e set up in
different stands, and these test plots were compared to others acting as
controls. The whole idea of this study was to prevent the tree sway and
this prevention of sway caused marked reduction in diameter growth in the
lower part of the bole.
- 55 -